Power Cable with Double Female Connector

My daughter has a 2008 Ford Focus (with 110k miles), indicated that the car had to be jump started twice recently, and I took a look this morning with an eye towards replacing the battery.

Sitting atop the battery was an unconnected red cord (with a female, two hole connector) that I simply do not know where it should be. I have attached a picture. Any insight would be greatly appreciated.